Add a dryrun mode to vote command to enable easier testing

[mixels]

Creating custom voting rewards is a bit of a challenge. To make sure everything is set up right, it would be nice to be able to test the /vote command. I suggest adding a /testvote command which does the same thing as the /vote command but without the vote claimed and has voted checks.

[niekcandaele]

This is a good idea! Instead of copying the command though, I would add an optional argument to the existing command. Something like $vote dryrun.

I think this will need some sort of permission check too, we don't want regular players to be able to trigger the reward without setting the vote as claimed.